Monday, February 21, 2011

After all the hullabaloo I’ve made about being able to align the blade with the miter slot on a saw with table-mounted trunions, it’s time to actually do the deed. I got myself a set of feeler gauges to help with measurements. On my first take, I used a method I’ve seen in several places on the internet. It doesn’t require a dial indicator, which I don’t own. A friend is going to let me borrow one, but if I’m serious about this stuff I need to get one myself. Another thing I’m going to borrow is a good-quality saw blade. That will help me rule out errors caused by a so-so blade instead of the saw. I’ll be getting some new saw blades for myself soon.

I started my test by squaring the miter gauge. If that was out of whack, then it would make everything else that much more difficult. That process proved to be kind of annoying, since the fence moves on the Ridgid miter gauge when you tighten it. After lots of trial and error (more error than trial), I think I got it squared pretty well. Next I made sure the saw blade was perpendicular to the saw table. With that accomplished, I found a piece of cherry that had been jointed to a right angle and clamped it to the miter gauge. I turned on the saw and ran it through, making sure to go through the entire blade. With the saw turned off and unplugged, I positioned the miter gauge so that the just-cut-off piece of wood was near the front of the saw blade. I chose a saw tooth and carefully moved it back and forth against the cherry to see how much it rubbed against it. Then I moved the miter gauge so that the wood was near the back of the saw. I turned the saw blade so that the tooth I tested earlier was next to the wood. This is the critical measurement. Ideally, there should be no gap between the wood and the tooth or, if there is a gap, it should be miniscule – as in less than 3/1000th of an inch.

I got out my set of feeler gauges and tried the one for 3/1000th of an inch. It slid in easily, so I tried 4/1000th and 5/1000th. Turns out that the gap was 6/1000 of an inch. While that isn’t a large gap in the real world, it is unacceptably large for woodworking. On the other end of the spectrum, 2/1000th of an inch or so is acceptable. We aren’t making parts for NASA. And even if we were, wood swells and contracts so much that those measurements are fairly meaningless.

In the next couple nights, using a good-quality blade and perhaps a dial indicator, I’ll confirm my measurements and attempt to align the blade if necessary. Stay tuned.

1 Comment:

Thanks for all of these updates!!! I ordered my R4512 from Home Depot and it is scheduled for delivery on 3/18/11. Will be using your comments and review as guidance for assembly, alignment, etc. so please don't be frugal with any explanations.